The embedded/appliance system (E/A system) in the digital telephony industry is traditionally targeted for the Small and Medium Business (SMB) marketplace. This business space is characterized by low profit/high volume for sales for the vendors of the embedded/appliance telephony systems. To be successful in this marketplace, the telephony systems are typically designed to be low cost in terms of manufacturing and cost of ownership for the end customer. The systems are also designed to require a relatively low amount of support from the vendor.
If a customer requires fault tolerance for the data storage (e.g. hard drive) of an E/A telephony system, current implementations will include the use of a Redundant Array of Inexpensive Disks (RAID) system. With the small physical foot print of an E/A telephony system, there is usually only enough physical space for two 2.5 inch data storage devices. This will limit the implementation to a RAID 1 (mirror) type of system that can be used only for fault tolerance.
While RAID 1 is an effective method of protecting against a single drive failure, such failure has a very low probability of occurrence. The chance of a catastrophic hard drive failure that cannot be recovered by software is actually quite remote with the technology available today for enterprise rated drives. Typical hard drives available today for use in industrial applications have an unrecoverable error rate on the order of 1 in 1016, resulting in an average of 0.55% annual failures per year under normal environmental operating conditions. For a standard consumer grade hard drive, the unrecoverable error rate is 1 in 1014 with an annual failure rate of 0.5% under normal environmental operating conditions.
While the RAID system is useful in protecting against loss of data, the system precludes the use of the second storage device in an E/A telephony system from being used for other purposes. With the low probability of data loss, the second storage device may be of more use to a customer in reducing the cost of manufacturing, ownership, and support.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.